Simple Interest & Compound Interest Concepts for SSC

Quantitative Aptitude is an equally important section for SSC CGL, CHSL, MTS exams and has an even more abundant importance in some other exams conducted by SSC. Generally, there are questions asked related to basic concepts and formulas of Simple Interest & Compound Interest.

To let you make the most of QUANT section, we are providing important facts related to Simple interest & Compound Interest. Also, Railway Exam is nearby with bunches of posts for the interested candidates in which quantitative aptitude is a major part. We have covered important notes and questions focusing on these prestigious exams. We wish you all the best of luck to come over the fear of Mathematics section.
Simple Interest & Compound Interest

Simple Interest

1. If a certain sum in T years at R% per annum amounts to Rs. A, then the sum will be


2. The annual payment that will discharge a debt of Rs. A due in T years at R% per annum is .Annual payment=



3. If a certain sum is invested in n types of investments in such a manner that equal amount is obtained on each investment where interest rates are R₁, R₂, R₃ ……, R_n, respectively and time periods are T₁, T₂, T₃, ……, T_n, respectively, then the ratio in which the amounts are invested is


4. If a certain sum of money becomes n times itself in T years at simple interest, then the rate of interest per annum is


5. If a certain sum of money becomes n times itself at R% per annum simple interest in T years, then


6. If a certain sum of money becomes n times itself in T years at a simple interest, then the time T in which it will become m times itself is given by


7. Effect of change of P, R and T on simple interest is given by the following formula:


8. If a certain sum of money P lent out at SI amounts to A₁ in T₁ years and to A₂ in T₂ years, then


9. If a certain sum of money P lent out for a certain time T amounts to A₁ at R₁ % per annum and to A₂ at R₂ % per annum, then


10. If an amount P₁ lent at the simple interest rate of R₁ % per annum and another amount P₂ at the simple interest rate of R₂ % per annum, then the rate of interest for the whole sum is


Compound Interest

1. (a) The amount A due after t years, when a principal P is given on compound interest at the rate R% per annum is given by


2. If the interest is compounded half-yearly, then


3. If the interest is compounded quarterly, then



4. When the rates of interest are different for different years, say R₁, R₂, R₃ percent for first, second and third year, respectively, then


5. When the time is given in the form of fraction, say 23/4 years, then,

 

6. (a) The difference between the compound interest and the simple interest on a certain sum of money for 2 years at R% per annum is given by


(b) The difference between the compound interest and the simple interest on a certain sum of money for 2 years at R% per annum is given by


7. If a certain sum becomes n times in t years at compound interest, then the same sum becomes n^m times in mt years.

8. If a certain sum becomes n times in t years, then the rate of compound interest is given by


9. If a certain sum of money at compound interest amounts to Rs. x in A years and to Rs. y in B years, then the rate of interest per annum is


10. If a loan of Rs. P at R% compound interest per annum is to be repaid in n equal yearly instalments, then the value of each instalment is given by

Learn to Solve Simplification & Approximation Questions


Simplification, and Approximation is a topic that is the easiest to solve and at least 10 questions asked in every examination. So, you can easily grab 10 marks in Aptitude Section if you are good at calculations. All that you need to do for this topic is to be fast with calculations and keep practicing, it will always stand you in good stead.

The important points to deal with this section are to remember the BODMAS Rule and have all the tables, cubes, squares entirely grasped.

Simplification and Approximation along with a few more calculation-based topics, is a topic that helps you score the maximum marks in the aptitude section. And to deal with this topic efficiently, you need to be excellent at calculation because that's the only thing that you need to do while solving the questions from this topic. If you lag here, this topic can prove to be a can of worms for you. Some people might wonder how there are people who can solve the toughest of these questions within minutes while others find it difficult to solve the simplest of them. But that’s just a mindset. The approach to this topic can be made easier when the questions are continuously being practiced by someone who is actually willing to improve. 

Here are a few tips on how to solve Simplification and Approximation questions efficiently:

1. Remember to have all the multiplication tables up to 20, squares up to 30, cubes up to 20, and fraction tables (1/n) entirely grasped.

2. Try to do most of the everyday calculations on your own. Check the Cricket Scores that are quite big in numbers, and try to perform Average, Subtraction, Multiplications and things can do a good turn in the examinations. While you travel, you can also check the car numbers while you travel and divide, multiply by the number of cars you marked. It will boost your calculation skills.

3. Continuous practice is always beneficial, as the candidate is able to find the correlation in some calculations, can observe a pattern and might develop a few tips and tricks on his own to solve that particular question. This helps the candidate in remembering what the answer will be to a particular calculation like addition or multiplication, which will eventually save the time during the examination.

4. For some of the questions on Simplification and Approximation, there is a technique or trick given by Vedic Math that may help candidates saving their precious time during the Examination. One must always know where a particular technique or trick is to be used while solving different questions.